Tuesday, August 13, 2013

1947-1955 Chevrolet Trucks

1950 Chevrolet Truck

The 1950 model year brought about the end of the postwar seller's market. Now, suddenly, America's insatiable appetite for anything on wheels came to an abrupt halt. Buyers were starting to pick and choose again (though they would make 1950 a record-setting year for car and truck purchases, spurred on to some degree by the start of war in Korea). Trucks had sold well during the previous four years, and Chevrolet had topped the market; total Chevy truck registrations had reached 345,519 by '49. But with buyers now in control, Detroit recognized that the sales race was about to heat up.
Even so, not much changed on 1950 Chev­rolet trucks. Horsepower and torque did increase by two on the Thrift-Master, to 92 horsepower at 3,400 rpm and 176 pound-feet at 1,000-2,000 rpm, thanks mainly to a revised Rochester carburetor and slightly bigger exhaust valves. Tubular rear shocks became standard, and the three-quarter-ton pickup now used eight-leaf front springs.

On panels and canopy expresses, a new single-sheet plywood load floor replaced multiple-board construction for better dust sealing. The Suburban resorted to single-tone standard paint and made available panel-style rear doors, marking the first time since 1946 that customers could choose between side-hinged doors or a top-and-bottom tailgate.

In 1949, Edward H. "Crankshaft" Kelley became Chevrolet's chief engineer. He continued to make minor improvements in the division's trucks, but he concentrated on his main areas of expertise, namely economy of manufacture and plant efficiency. Under Kelley's direction, Chevy's 1951 pickups lost some of their previous standard equipment, notably the rear bumper and spare-tire locks. But he did add conventional door-window ventipanes to replace the cowl vent on the driver's side.

1951 Chevrolet Truck

The 1951 Chevrolet truck got a more-durable and wider "double-decker" seat. This used two layers of springs, one atop the other. The seat adjuster went to a combination of ball and roller bearings instead of the former double rollers on a central shaft.

Another 1951 upgrade was the addition of self-energizing Bendix brakes. Here, as in passenger cars, the rotation of the drums provided some of the energy needed to force the shoes outward against the drums. This meant that the driver didn't have to push so hard on the pedal; the self-energizing action kicked in automatically whenever the driver touched the brakes.

The front stabilizer bar now bolted farther inboard on the front axle beam and attached via an articulating link, and the front stabilizer bushings mounted directly to the chassis frame. This improved cornering stability and cost less to manufacture.

Chief engineer Edward Kelley's team also adopted a swing-down spare carrier that nestled underneath the rear of the pickup bed. The new carrier moved the tire farther forward, and without the rear bumper, the tailgate could drop straight down. In the past, the unchained tailgate came to rest against the bumper.

All 1951 pickup boxes were reinforced by welding the cross sill to the stake pockets at two spots on each side. Before, heavy loads could spread the side panels so that the tailgate wouldn't lock. There were also now eight slightly wider boards for the pickup floor instead of nine, along with one fewer metal rub strip.

New accessories included a windshield washer, grille guard, plus a handheld spotlight that plugged into the optional cigar lighter. Due to the Korean military action, chromium became a rare commodity in 1951. Most Chevy trucks came with the standard painted grilles. Then for 1952, chrome plating disappeared almost entirely. A bright grille no longer was offered, even for Suburbans, and series badges disappeared from the hood sides of half-tons. Because the Korean conflict also put a hold on copper, radiators became lighter and less robust, too.

1952 Chevrolet Truck

You had to look carefully to tell a 1952 Chevrolet truck from a ’51. The major visual clue was the outside door handle. Chevrolet trucks had used the twist type through 1951, but switched to the pushbutton style for 1952. One-ton models adopted the floor-pedal parking brake. Thistle Gray became the new color for inner grille bars.

Despite this seeming sameness, activity was taking place inside Lu Stier’s styling studio located in Fisher’s Plant Eight facility during 1952. Plant Eight was located a few blocks away from the Argonaut Building, where Harley Earl officiated over the GM Styling Section.

One member of Stier’s design group was Chuck Jordan, who would eventually rise to the position of vice president of design. Now retired to Cal­ifornia, Jordan joined GM in 1949. All design interns started in the orientation studio, which happened to be on the fourth floor of Plant Eight, next door to Stier’s truck studio. Jordan had always been fascinated with trucks -- he’d learned to drive one at age 12 on his father’s orange ranch -- so when it came time to pick a studio in which to work, he chose Stier’s.

In addition to chief designer Stier, members of the studio at that time included designers Bob and Al Phillips (who were not related), modeler Clark Whitcomb, and woodworker Frank Wagner. There was no assistant chief designer, says Jordan, because it was such a small studio.

When he got there, recalls Jordan, “We were working on a facelift of the original 1947 truck, and we did a lot of sketches knowing that we could only do a grille and ornamentation. I think we also did an instrument panel. So we were all working on that project and, as a first experience, it was wonderful, because Lu Stier didn’t act like a big boss. He was one of us, just a low-key guy, always pleasant, never temperamental, never dictatorial; just did what he had to do to run the studio. And he also worked with us as a fellow designer.

“We’d talk about things as we put them on the wall, and he just moved right ahead. We didn’t have any program or any rules or anything. When we saw something that was good, we tried it. It was a wonderful environment.”

Stier’s immediate boss was Al Boca. Boca came into the studio occasionally, but Jordan doesn’t feel he had much authority or influence. He acted more as a liaison between the studio and Chev­rolet engineering. Engineers would visit often since the truck bodies were all engineered by the division. That put Jordan in his element, considering he’d taken his Massachusetts Institute of Technology degree in mechanical engineering, though he knew all along that he wanted to devote himself to styling and body design.

According to Jordan, Earl did not visit the truck studio very often. “No one came to give us instructions. Everyone pretty much left us alone. But there was one time when Harley Earl did come in. It was on a Saturday. We were all working overtime ... so here we were, all in jeans and T-shirts on a Saturday, and here comes Harley Earl walking in bigger than life. I’d seen him before, but I’d never been in a working relationship with him.

“So we’re all standing there with our knees knocking as he came in. ... He walked into the studio and always worked in front of a full-sized board. He worked on line. He couldn’t sketch. He’d look at sketches, but on this particular Saturday, he’d come over with an idea.

“He said, ‘Fellas, I g-g-got an idea,’ the way he stuttered, and he sat down in front of the board with his legs splayed out, and we’re all standing behind him, wondering what was happening. He said, ‘Now here’s what I want to do,’ and he described an early version of an El Camino pickup.”
According to Jordan, Earl spent several hours in the studio. Jordan was asked to modify the roofline, lowering it an eighth of an inch. “I tell you, that was one of the hardest things I ever did, because my hands were shaking. That was my first experience with Harley Earl,” he says.

The passenger-car-based pickup was to have been built on a 1952 Chevrolet sedan base. It seemed like a great idea, and it excited everyone in Stier’s studio. But Earl later lost interest in the project. Jordan doesn’t know why. The early “El Camino” was never modeled in clay or built as a prototype. But the idea was resurrected, of course, for 1959, and the resulting production El Camino was the first of a successful line.

Then, too, in May 1952, Edward N. Cole became Chevy’s chief engineer. Cole immediately focused on the 1955 line of cars and trucks, particularly the development of Chevrolet’s small-block V-8. While he did tweak the 1954 cars and trucks, these changes were overshadowed by work on the V-8 and the totally changed 1955 models.
Tinted glass was available on 1953 Chevy trucks.

1953 Chevrolet Truck

The minor differences that appeared in Chevrolet's 1953 truck line included new paint colors, restyled hoodside series designation plates (created by future design vice president Chuck Jordan, his first design element to reach production), slightly heavier front shock absorbers, modifications to the three-speed transmission to keep it from popping out of high gear, and a lower horn note. Hubcaps were now attached to the wheels by three wide clips instead of six narrow ones, and the parking-brake release handle was repositioned farther to the left to make disengagement easier.

New 1953 options included tinted glass and a sidemount spare-tire carrier between the cab and the left rear fender. The accessory oil filter was fed through a flex hose instead of metal tubing.

Ed Cole put on a relatively big push to improve Chevrolet's 1954 truck lines, but his main effort still centered on the V-8. He realized that the new engine would completely transform Chevrolet, both in its passenger cars and in its trucks. So the 1954 changes came in anticipation of an entirely upgraded range of 1955 trucks.

1954 Chevrolet Truck

Although a complete makeover was in the works for the following year, the 1954 Chevrolet truck did get a facelift, including a switch to a one-piece curved windshield. Chief engineer Ed Cole also discontinued the 216.5-cubic-inch Thrift-Master Six and replaced it with the 235.5-cubic-inch engine from Chevy's larger Load-Master trucks.

According to designer Chuck Jordan, the 1954 facelift involved "choosing sketches off the wall, but we had to continue the front-end sheetmetal that Chevy gave us. We mounted a complete production 1953 front end] on legs and tried different grilles. We had to use the same hood, same fenders. ... Our job was to just fill the hole," he says. Designer Lu Stier's crew wound up with a single thick horizontal bar bisected by a stubby vee'd center bar, low rectangular parking lights, a new hood ornament, and hubcaps sporting Chevy "bow ties."

In addition to the visual revisions, Cole's group reduced the rear frame kickup to give the pickup bed a lower loading height. This allowed for pickup bed sides to be raised 2.25 inches on all models -- and three-quarter-ton pickups gained even more cargo capacity by a three-inch stretch of bed length to 90 inches. The new pickup boxes also now incorporated horizontal top rails. (This box design would go on to serve Chevy pickups into the Eighties.)

The truck engineering team beefed up the frame crossmember behind the engine, increased standard clutch diameter from 9.13 to 10 inches, and made four transmissions available: an all-synchro three-speed (standard in 3100s and 3600s); a four-speed all synchro gearbox with floorshift (standard in 3800s, optional in others); a heavy-duty all-synchro three-speed; and, for the first time, GM's four-speed Hydra-Matic automatic. The heavy-duty three-speed and Hydra-Matic could be ordered for any light-duty truck model. A 3.9:1 axle ratio was used in 3100s for greater fuel economy.

The 235.5-cubic-inch engine had been extensively tweaked for 1953, and was even more so for 1954. The head got a tighter 7.5:1 compression ratio, up from 7.1:1. Horsepower jumped to 112 at 3,700 rpm, torque was now 200 pound-feet at 2,000 rpm, and refinements included full-pressure lubrication, aluminum pistons, stronger connecting rods, a built-up crankshaft for greater stiffness, thicker bearing bulkheads for a beefier crank-case, bypass cooling, and improved distributor insulation.

A redesigned dashboard featured twin instru­ment dials that were slightly recessed, the speaker grille bars were now vertical instead of horizontal, and the upper portion of the dash bulged out slightly over the working section. Finger grips were added to the steering wheel. The seat was upholstered in brown leatherette, set off by beige trim and paint. Defroster openings extended fully beneath the one-piece windshield.

Dealer-installed accessories included turn signals, multicolor seatcovers, a dash-mounted clock, radio, heater, non-glare inside mirror, cigar lighter, and two types of grille guards. One of the more popular factory options was the Deluxe Comfortmaster Cab, which included maroon-and-gray fabric and trim, Nu-Vue corner windows, chrome window moldings, a passenger-side sun visor, driver's armrest, cigar lighter, and dual horns. Panel trucks could still be had with a deluxe package, as well. Also listed as options were electric windshield wipers and a foot-operated windshield washer.
Early 1955 Chevy trucks were the last of the stalwart post-war designs.

1955 Chevrolet Truck

The early 1955 Chevrolet trucks, generally called "First Series" '55s, were sold through March. At that point, they were replaced by completely re-engineered and restyled "Second Series" '55s, which promptly set a new standard for American trucks.

On the surface, the First Series trucks looked like a straight continuation of the 1954 models, but there were differences. For appearance sake, new hoodside series badges were applied, and grille bars adopted Bombay Ivory as the standard color. In the technical department, an open drive-shaft replaced the torque tube that had been a Chevrolet engineering staple. The early '55s also marked the end of the line for the canopy express; new shopping habits were ringing out the era of wares sold door-to-door from "peddler wagons."

Time had surely run out on the Advance-Design trucks by '55, considering Ford had totally redesigned its trucks for 1953 and Dodge had followed suit the following year. But these hardy Chevys were sales champs throughout their long run. Today, many of them still soldier on with grace and dignity, adding testimony to the durability and ruggedness -- the correctness -- of their design and engineering.

Source: HowStuffWorks